Phase Change Materials in Hot Water Generation Systems: A Review

Solar hot water generation systems are still a valuable technology for reducing carbon dioxide emissions to the environment. These systems can be used for extended periods when integrated with phase change materials (PCMs). Because of this advantage, the main objective of this article is to review the last five years of studies, including experiments, improvements, and the materials used as PCMs for domestic hot water (DHW) generation. A search strategy consisting of keywords and search equations was proposed, allowing this study to find 51 relevant articles. From them, it was found that the most commonly used PCMs are paraffins. In addition, experimental validations mainly focused on the working fluid and PCM and the charge and discharge conditions. Likewise, improving the thermal conductivity of PCMs can help positively by increasing the performance of TES (thermal energy storage) systems for hot water generation.